Concrete - Optex Fiber SenSys Terrain Defender TD 100 Installation Manual

o If the crushed stone layer is >10 cm (>4 in), reduce the burial depth equally every
additional inch up to 16.5 cm (6.5 in). For example, 12.7 cm (5 in) top cover in crushed
stone would require 20.3 cm (8 in) burial depth, 2.5 cm (1 in) additional crushed stone
reducing the total burial depth by 2.5 cm (1 in). If clay is present, then that would need to
be compensated for. Work with a Fiber SenSys Support Representative to determine the
best method when installing TDSC.
o If the crushed stone layer is >16.5 cm (>6.5 in), the concrete installation procedure may
need to be utilized. Work with a Fiber SenSys Support Representative in all cases of
crushed stone greater than 16.5 cm (6.5 in) to verify TDSC installation prior to
deployment.
o The maximum size for the crushed stone is 19 mm (0.75 in).

Concrete

Concrete installation significantly differs from the above installation methods due to its
density.
o A 6.4 cm (2.5 in) deep, 1.8 cm (.71 in) wide slot will be required for concrete =>10 cm
(>4 in) thick. For concrete <10 cm (<4 in), work with a Fiber SenSys Support
Representative to determine the best installation method.
o Before placing the sensor cables into the slots, verify there are no sharp edges, and the
slot is free from debris. Inserting a 1 m (3.3 ft) section of scrap sensor cable is a simple
tool to verify your slot depth and width spot-checking every 2 - 3 m (6.6 – 10 ft) before
handing the TDSC spool.
o Once the sensor cable is set into the slot, a 3/4 in (1.9 cm) foam backer rod is placed on
top of the sensor cable then sealed with DOWSIL™ 888 Silicone Joint Sealant.
CAUTION: Concrete reinforced with metal rebar can cause the detection field to stray
away from the sensor lines. Greater than 5 cm (2 in) below TDSC is acceptable,
otherwise, for proper field containment on reinforced concrete, consult with a Fiber
SenSys Support Representative with details on the rebar placement and concrete
design.
Note: 13 mm (1/2 in) space is necessary above the backer rod and slot top for proper
sealant bonding.
Page 29
Figure 21. DOWSIL™ 888 Silicone Joint Sealant
Confidential – Limited Distribution